Monitoring Avian Productivity and Survivorship (MAPS)

Science Center Objects

Dr. Barbara Kus is a partner in an international bird-monitoring program to provide long-term data throughout North America. MAPS or “Monitoring Avian Productivity and Survivorship”, uses capture and banding data to compile basic demographic parameters of migratory species, many of which are imperiled regionally and even globally. Age- and sex-specific data on annual survival, reproduction, and recruitment can be gathered and compared across stations to identify population trends for species of interest and can be used to identify proximate factors responsible for trends; in particular, negative trends. In turn, information obtained from long-term monitoring of bird populations can be used to guide management activities intended to maintain or re-establish viable populations throughout the species’ ranges.

Protection and management of endangered birds is a primary focus of resource managers and state and federal wildlife agencies. However, many species or groups of species not listed exhibit population declines which, if continued, will likely place the species at risk of extinction. Neotropical migratory birds, or birds that breed in temperate regions and winter at tropical latitudes, are one such group. Long-term data from the North American Breeding Bird Survey (BBS) and other sources suggest that many neotropical migratory species are declining, prompting action by governmental, non-governmental and private organizations to develop coordinated monitoring and research of neotropical birds. Central to these efforts is the goal of preventing future listings through an ability to detect, identify the causes of, and reverse declines in species before they reach critically low numbers, at which point the potential for recovery is limited.

A WERC scientists collects field information at a MAPS station.(Credit: Barbara Kus, USGS, WERC. Public domain.)

MAPS is a collaborative program that in addition to an index of population size, provides critical demographic information necessary for explaining population trends. Modeled after the British Trust for Ornithology’s Integrated Population Monitoring Program, MAPS is a standardized constant-effort protocol that uses mist-netting and banding data collected during the summer nesting season. Capture-recapture analysis of banded birds provides data on sex- and age-specific annual survivorship and recruitment, while ratios of adults to juveniles captured yield an estimate of annual productivity. These data allow determination of the stage(s) of the life cycle at which population limitation is occurring, which in turn provides a guide for investigation of potential causal factors. Given the wide range of possible explanations for declines in neotropical migrants, including loss and degradation of breeding habitats, deforestation of tropical wintering habitats, mortality during migration, cowbird parasitism, and predation, it is essential that research be directed towards factors most likely to account for a particular species’ decline based upon the demography of that species. This ability serves as an "early warning" system which allows for the fine-tuning of local and regional conservation efforts in a manner that directs management attention in an efficient and timely manner to the species in need of it.